|
|
| Line 1: |
Line 1: |
| − | ===Simple Linear Regression===
| |
| − | <!-- [[File:SimpleLinearRegression.png|350px|thumb|center|]] -->
| |
| | | | |
| − | [[File:SimpleLinearRegression2.png|600px|center|]]
| |
| − |
| |
| − |
| |
| − | The purpose of regression analysis is to:
| |
| − | * Predict the value of the dependent variable as a function of the value(s) of at least one independent variable.
| |
| − | * Explain how changes in an independent variable are manifested in the dependent variable
| |
| − | :* The dependent variable is the variable that is to be predicted unexplained.
| |
| − | :* An independent variable is the variable or variables that is used to predict or explain the dependent variable
| |
| − |
| |
| − |
| |
| − | '''The regression equation:'''
| |
| − | <math> y = a + bx </math>
| |
| − |
| |
| − | * Dependent variable: <math> y </math>:
| |
| − | * Independent variable: <math> x </math>:
| |
| − | * Slope: <math> b = r \frac{S_y}{S_x}</math>
| |
| − | : The slope is the amount of change in units of <math>y</math> for each unitchange in <math>x</math>.
| |
| − | * <math> y </math> intercept: <math> a = \bar{y} - b\bar{x} </math>:
| |
| − |
| |
| − |
| |
| − | <br />
| |
